Multiple cutting head assembly for auger mining machine

ABSTRACT

A multiple cutting head assembly for an earth auger machine such as for mining coal from an open pit. The multiple cutting head assembly has a plurality of rotatable cutting heads rigidly fixed to helically vaned head augers with parallel, coplanar axes journaled in a rigid frame. The cutting heads and helically vaned head augers are rotated by strings of auger sections to cause the cutting head assembly to move into a mineral vein to be mined. The frame has front and rear bearing housing assemblies and individual removable bearing retainer caps for securing journal bearing units. Each head auger comprises an auger tube with a front shaft and shank shaft welded in its forward and rearward ends respectively, the shafts being journaled in bearing units of the front and rear bearing housing assemblies. A rotatable cutting head is removably but non-rotatably secured to the front shaft of each head auger unit forwardly of the front bearing housing assembly. Each head auger may be removed from the rigid frame for repair, by disconnecting the respective bearing retainer caps from the front and rear cross members and then lifting the head auger from the assembly. Dust-resistant seals are provided at the bearing units.

United States Patent [191 Deeter et al.

[ 1 Oct. 14, 1975 MULTIPLE CUTTING HEAD ASSEIVIBLY FOR AUGER MINING MACHINE [75] Inventors: Ronald C. Deeter, Malvern; Thad A.

Lora, Salem, both of Ohio [73] Assignee: The Salem Tool Company, Salem,

Ohio

22 Filed: Nov. 6, 1974 21 Appl. No.: 521,332

Primary Examiner-Ernest R. Purser Attorney, Agent, or FirmBosworth, Sessions & McCoy [57] ABSTRACT A multiple cutting head assembly for an earth auger machine such as for mining coal from an open pit. The multiple cutting head assembly has a plurality of rotatable cutting heads rigidly fixed to helically vaned head augers with parallel, coplanar axes journaled in a rigid frame. The cutting heads and helically varied head augers are rotated by strings of auger sections to cause the cutting head assembly to move into a mineral vein to be mined. The frame has front and rear bearing housing assemblies and individual removable bearing retainer caps for securing journal bearing units. Each head auger comprises an auger tube with a front shaft and shank shaft welded in its forward and rearward ends respectively, the shafts being journaled in bearing units of the front and rear bearing housing assemblies. A rotatable cutting head is removably but nonrotatably secured to the front shaft of each head auger unit forwardly of the front bearing housing assembly. Each head auger may be removed from the rigid frame for repair, by disconnecting the respective bearing retainer caps from the front and rear cross members and then lifting the head auger from the assembly. Dust-resistant seals are provided at the bearing units.

8 Claims, 8 Drawing Figures 54a u mf 381 84 52 w 42 84 26 -4 540 i D a 84 n 84 5 53 56 a 42 5. 89 2a 7 27 U.S. Patent Oct.14,1975 sheen Om 3,912,025

FIG. I.

US. Patent 0a. 14, 1975 Sheet 2 of 3 3,912,025

wn |m\ mm mm MW i mm mm N wm 5 mm mm vm US. Patent Oct. 14, 1975 Sheet 3 of3 3,912,025

MULTIPLE CUTTING HEAD ASSEMBLY FOR AUGER MINING MACHINE BACKGROUND OF THE INVENTION This invention relates to auger-type machines for mining coal, for example, and especially to a machine, usually located in an open pit adjacent an upright wall, that laterally advances a rotary cutting head progressively into a vein or seam of material to be mined to cut a relatively deep lateral hole while conveying the spoil rearwardly from the cutting head with helical auger flights. Additional auger sections are added on as needed to form a string of auger sections corresponding to the depth of the hole. More particularly, the invention relates to cutting head assemblies with multiple rotary cutting heads journaled in rigid frame with their respective axes generally parallel and generally coplanar. The resulting assembly is advanced longitudinally as a unit laterally into the mineral vein in the earth to cut a relatively wide hole as the mining progresses. Preferably a multiple cutting head assembly is advanced into a mineral vein, such as a seam of coal, to a thickness corresponding to the thickness of the seam and to a depth corresponding to the number and length of auger sections being used. As the cutting head assembly progresses, coal is conveyed rearwardly to the pit by the helically vaned auger sections and then removed from the pit by other equipment.

Where a multiple cutting head assembly is used, separate strings of auger sections extend from the main body of the machine to the cutting head assembly to rotate the multiple cutting heads simultaneously and to exert a thrust against the head augers which is transmitted to the rigid frame through the journal bearings, when the cutting head assembly is advanced and to exert a pulling action on the cutting head assembly when it is withdrawn from the cut hole.

The cutting head assembly must be capable of withstanding the forces arising from the large amounts of power supplied to the assembly to rotate and advance its cutting heads, and to withdraw the assembly from the hole.

Each head auger comprises an auger sleeve or tube with a front shaft fixed to its forward end and a shank shaft fixed into its rearward end. Both shafts are journaked in cross members at the front and rear of the frame. The bearing housing assemblies are normally held together with tie bars and the journal bearings are permanently anchored in the front and rear cross members. The cutting head is bolted to the front end of the front shaft.

The cutting heads for these machines, as well as the entire head auger assemblies, must be removed and replaced periodically because of wear or damage incurred in mining. The prior art constructions require for such removal and replacement, that the front and shank shafts be unfastened and pulled axially from their journal bearings and from the auger tube. This is often extremely difficult because the shafts tend to freeze in the head auger sleeves after extended use and tremendous force must be exerted or even that parts be cut away.

These problems are accentuated when it is desired to provide a cutting head assembly that is sufficiently thin to enable it to mine relatively thin seams of coal or other minerals, as is desirable in view of the increasingly high economic value of the coal or other mineral.

The improvement of the present invention greatly reduces the difficulties indicated above and affords other features and advantages heretofore not obtainable.

SUMMARY OF THE INVENTION It is among the objects of the invention to facilitate replacement of head augers in multiple cutting head assemblies for auger mining machines.

Another object of the invention is to reduce the thickness for a multiple cutting head assembly for an auger mining machine.

A further object is the provision of means for journaling the various head auger assemblies in a rigid frame structure in such a way that cutting forces and loads exerted against each head auger of the cutting head assembly are transmitted to the rigid frame that serves to hold the respective cutting head assemblies in proper relation to one another as the cutting head assemblies are advanced into the earth. A further object is the provision of means for protecting the journals against entrance of dirt or other material that could cause damage.

These and other objects and advantages are achieved with the improved multiple cutting head assembly construction of the present invention as used in association with an earth auger machine of the type described above. The machine has power means for advancing the cutting head assembly into the earth and providing the necessary rotary drive for the cutting heads. The multiple cutting head assembly includes a rigid frame for holding the cutting head assemblies in proper relationship during their advance into the earth. Each frame includes a front bearing housing assembly and a rear bearing housing assembly, the housing assemblies being secured to one another as by tie bars. Each of the bearing housing assemblies includes a cross member, a plurality of bearing retainer caps adapted to be removably connected to the respective cross member and a plurality of journal bearing units one being retained between each cap and the respective cross member.

A plurality of head augers are rotatably supported by the frame with their axes parallel and preferably subtantially in a common plane. Each of the head augers comprises an auger tube with spoil conveying external helical flights, a front shaft fixed as by welding, to the front end of the head auger tube journaled in the front bearing housing assembly, a shank shaft fixed as by sponse to thrust exerted in an axial direction through.

the string of auger sections to the respective head augers.

Of particular importance, each of the head augers may be selectively removed from the rigid frame by disconnecting the respective journal bearing caps from the respective cross members.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a broken plan view to a greatly reduced scale of an auger-type mining machine having a multiple cutting head assembly embodying the invention;

FIG. 2 is a plan view on a larger scale showing a multiple cutting head assembly embodying the invention with the three cutting head assemblies each latched to a coaxial auxiliary auger section forming part of the string;

FIG. 3 is a sectional view on an enlarged scale taken on the line 3-3 of FIG. 2;

FIG. 4 is a sectional view on a still larger scale taken on the line 44 of FIG. 2;

FIG. 5 is a sectional view to the same scale as FIG. 4 taken on the line 55 of FIG. 2;

FIG. 6 is a sectional view taken on the line 66 of FIG. 4 and to the same scale;

FIG. 7 is a sectional view taken on the line 77 of FIG. 7 to the same scale;

FIG. 8 is a sectional view taken on the line 8-8 of FIG. 5 and to the same scale.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly to the drawings and initially to FIG. 1, there is shown a horizontal auger-type mining machine A with a multiple cutting head assembly B embodying the invention and adapted to be advanced into a mineral vein in the earth by a carriage C mounted on the main frame 10 of the machine A, and adapted to travel along parallel ways 11 and 12 on wheels 13.

Means for advancing and retracting the carriage C is provided, one such being disclosed in US. Pat. No. 3,663,062, and thus need not be disclosed in detail herein.

An internal combustion engine 15 constituting a power source for rotating the angers is mounted on the carriage C and drives through a power train including a clutch 16, a shiftable transmission 17 and a flexible coupling 18. The output shaft of the coupling 18 is operatively connected to a gear box 19 adapted to drive three driving heads 21, 22, and 23. The driving heads are each connected to one of three auxiliary auger sections 25, 26, and 27 which are connected through known shank and socket type couplings, secured by a latch means which may be known means, to either the cutting head assemblies of the multiple cutting head assembly B or to other auger sections forming part of a string of augers. Socket means 28 is shown on each section 25, 26, 27.

The multiple cutting head assembly B comprises three cutting head units 31, 32, and 33. Units 31, 32, and 33 are coaxial and have their axes generally in a common plane. They are rotatably supported in a main frame 35 which holds the units in proper relation to one another and also provides a housing for journal bearings. The frame 35 comprises a transverse front bearing housing member 36 and a transverse rear bearing housing member 37, these transverse members being rigidly secured to one another by parallel longitudinal members 38 and 39 that are respectively located between units 31 and 32, and 32 and 33. The novel construction of the bearing housing assemblies 36 and 37 in accordance with the invention will be described in more detail hereinbelow.

The cutting head units 31, 32 and 33 (FIGS. 2-7) each comprise a head auger 41 including a head auger tube 42 with external helically vaned flights 43 secured thereon as is well known in the art, a front shaft 44 welded to the forward end of the tube and a shank shaft 45 welded to the rearward end of the tube. A cutting head 51, 52, or 53 is removably connected to the forward end of each front shaft 44 on the forward side of the front bearing housing member 36. The cutting heads 51, 52, and 53 are of generally conventional construction.

Each cutting head 51, 52, and 53 (FIGS. 3, 4) includes a generally cylindrical body 54 which carries known cutting elements 54a which are moved by the body through a circular path and advanced into the mineral vein to be mined. Located within and fixed to the cylindrical body 54 is a known breaker 55 which is adapted to break loose the material within the annular zone cut by the cylindrical body 54. The breaker is mounted on a tubular hub 56 and includes a plurality of cutting elements that revolve with the cylindrical body 54. The cylindrical body 54 is also attached to the hub 56 by helical vanes 58 in a known manner. Each of the cutting heads 51, 52 and 53 is attached to its associated front shaft 44 by a cap screw 59 which extends axially through a transverse plate 550 on hub 56 into a threaded axial bore in the forward end of shaft 44.

The front shaft 44 is of stepped configuration and includes an enlarged cylindrical rearward end 61 that is received in the front end of its associated head auger tube 42 and welded thereto. Intermediate the ends of the front shaft 44 is an intermediate cylindrical bearing portion 62, of smaller diameter than portion 61 and separated from it by shoulder 62a, which is machined to provide a suitable bearing surface and which is journaled in a bearing as described below.

A forward cylindrical portion 63, of smaller diameter than portion 62 and separated from it by shoulder 63a, extends forwardly from bearing portion 62 and is received within the hub 56. The forward end 63 has an axially extending slot 64 that receives a key 65 that is also seated in a cooperating slot 66 in hub 56. The rearward end of hub 56 bears against a bearing retainer sleeve 67 also received on the forward end 63 of the front shaft 44 and which is retained between the rearward end of the breaker tube 56 and a shoulder 62a between the intermediate cylindrical bearing portion 62 and the forward end 63 of the front shaft 44.

The shank shaft 45 (FIGS. 2, 7,) includes a cylindrical forward end portion 71 received within and welded to the rearward end of its associated head auger tube 42.

As with the front shaft 44, the shank shaft 45 is of a stepped configuration and includes an intermediate cylindrical bearing portion 72, of smaller diameter than portion 71 and separated from it by shoulder 72a, that is machined to provide a suitable bearing surface. To the rear of bearing portion 72 is another cylindrical port-ion 73 of lesser diameter than portion 72 and separated by shoulder 73a, and with an externally threaded portion 74 at its rearward end. Extending rearwardly of the threaded portion 74 is a square shank 75 adapted to be received in a matching socket in socket means 28 (FIGS. 2, 8) of another auger section 25, 26, or 27 forming a part of an auger string through which the respective cutting head unit 31, 32, and 33 is driven.

The shank 75 has a latching bore 77 formed therein that cooperates with a known latching means for detachably securing the shank and its socket together in a known manner.

Both the front shaft 44 and shank shaft 45 of each cutting head assembly are journaled in the front and rear bearing housing members 36 and 37 respectively, the construction of which are best illustrated with reference to FIGS. 3, 4 and 5. Since the bearing assemblies for both the front bearing housing member 36 and rear bearing housing member 37 are substantially identical they will be discussed primarily with respect to the front bearing housing assembly 36. Like parts in the rear bearing housing assembly 37 as illustrated in FIG. 5 will be identified by like numerals.

Bearing housing member 36 carries three antifriction roller bearings 80, of conventional construction, adapted to support both substantial radial and axial loads. Each bearing 80 is mounted on portion 62 of shaft 44 of its associated cutting head unit, its inner race being located between shoulder 62a on the shaft and ring 67 that is pressed against the race by the force exerted by bolt 59 through hub 56. Each bearing is mounted in member 36 by bearing retainer caps 81, 82, and 83 that are fastened to the member 36 by bolts 84 extending through member 36 and threaded into the retainer caps. Member 36 and retainer caps 81, 82, and 83 are formed with semicylindrical surfaces 85, 86, so that each bearing 80 is snugly seated therebetween. Each bearing 80 is retained against axial movement relative to member 36 by two retainer rings 87 and 88 that engage opposite sides of the outer race of the bearing. The retainer rings 87 and 88 are clamped against opposite sides of the member 36 and associated cap 81, 82 or 83 by six bolts 89 which extend axially from ring 88 through member 36 or retainer cap to a threaded bore in ring 87. The bearing 80 each have a pair of known spring-compressed seal rings 90 mounted on opposite sides of the bearing and respectively engaging cylindrical inner sealing surfaces of rings 87 and 88 and cylindrical outer sealing surfaces of ring 67 and shaft portion 61.

Each assembly including a bearing 80 in member 36 also includes a labyrinth seal 91 providing a tortuous annular passage 92 between rings 67 and 87 at the front side of the bearing facing the opening cut by the cutting heads, to aid in protecting the bearing against dust and other possible damaging material.

The mounting of the bearings 80 in the rear member 37 is best illustrated in FIG. 5 wherein parts corresponding to those discussed above are identified by like numerals.

In this case, however, the inner race of each bearing 80 is located between shoulder 72a of each rear shaft portion 45 of each cutting head unit and a retainer sleeve 94 threaded on threaded portion 74 of shaft portion 45, and held against rotation by a ring 95 apertured at 76 and shaped to fit closely over the polygonal cross section shank 75, and demountably fixed to ring 94 by screws 96.

The bearings 80 are held on member 37 by retainer caps identical with caps 81, 82, and 83 of member 36, between semicylindrical surfaces 85, 86 on member 37 and the caps, and by retainer rings 87 and 88 and bolts 84, as are the bearings on member 36. Sealing rings 90 are provided on both sides of the bearing between inner sealing surfaces on rings 87 and 88 and outer sealing surfaces on shaft portion 71 and ring 94.

A labyrinth seal 96, having a tortuous annular passage 97 is provided at the front side of the bearing between ring 87 and a labyrinth sealing ring 98 welded to shaft portion 71.

- In operation, torque for driving the three cutting head units 31, 32 and 33 is transmitted to their respective head augers 41 through their respective shank shafts 45 from the driving heads 21, 22, and 23 through auger strings that may include one or more auxiliary auger sections. All of the cutting head units 31, 32 and 33 are turned simultaneously in their respective roller bearing units 80, and they are held in proper relation to one another during their rotary cutting movement by the main frame 35.

The forces for advancing or retracting the multiple cutting head assembly B are provided by the carriage C and transmitted to the respective cutting head units 31, 32 and 33 simultaneously through the shank shaft 45 of the three head augers 41.

A major advantage provided by the present invention is that the arrangment for mounting the cutting heads in the cutting head units and the cutting head units in the front and rear members 36 and 37 of the frame 35, permits convenient removal and replacement of some or all of the cutting heads 51, 52, 53 themselves, or some or all of the cutting head units 31, 32 and 33 as a whole, or repair or adjustment of some of all of the bearings or seals, as desired. In prior art constructions the removal of a cutting head unit from the frame required that the front shaft and shank shaft be pulled in an axial direction out of the respective auger and axially out of the respective bearing housing assembly. Removal, however, in accordance with the construction of the present invention is achieved in an entirely different manner. According to the present invention removal is accomplished by removing the respective retainer caps 81, 82 or 83 from the respective cross members by removing the bolts 84 and then removing the axial bolts 89 that extend through the bearing retainer rings and through the retainer cap. This permits the cap to be removed and permits the entire cutting head assembly to then be removed with the front shaft 44 and shank shaft 45 still in position. 7

With the unique construction thus defined, repair can be accomplished much more conveniently and rapidly in the field. This is particularly advantageous in view of the limited space within which the removal and replacement operation must often be performed, and the need to reduce lost production time as much as possible.

It will be understood that the invention may be used, for example, where only two cutting heads assemblies, as well as where more than three such assemblies, are supported in the main frame. Also, the construction is not limited to mining operations, the auger-type mining machine described herein representing only one typical application for the invention.

Various other modifications may be made. Thus, labyrinth seals may be provided on both sides of each bearing, the bearing and seals other than those diclosed may be used.

While the invention has been shown and described in connection with a specific embodiment thereof, this is intended for the purpose of illustration rather than limitation and other modifications and variations in the specific construction herein shown and described will be apparent to those skilled in the art all within the intended spirit and scope of the invention. Accordingly, the patent is not to be limited in scope and effect to the specific embodiment herein shown and described nor in any other way that is inconsistent with the extent to which the progress in the art has been advanced by the invention.

We claim:

1. A multiple cutting head assembly for an earth augering machine having power means for advancing said cutting head assembly into the earth and for providing a rotary drive, said assembly comprising:

a rigid frame having a front bearing housing assembly and a rear bearing housing assembly rigidly connected to said front bearing housing assembly, each of said bearing housing assemblies comprising a cross member,

a plurality of bearing retainer caps adapted to be removably connected to said cross member and a plurality of journal bearing units, one being retained between each cap and the respective cross member,

a plurality of head augers rotatably supported by said frame with their axes parallel and approximately in a common plane, each of said head augers comprising an auger tube with spoil conveying external helical flights,

a front shaft rigidly connected to the front end of said auger tube and journaled in said front bearing housing assembly, a shank shaft rigidly connected to the rearward end of said auger tube and journaled in said rear bearing housing assembly, a rotary cutting head removably secured to said front shaft forwardly of said front bearing housing assembly, and means for connecting said shank shaft to said power means whereby all of said head augers are rotated in their respective journal bearing units as said cutting head assembly is advanced into the earth and whereby each of said head augers may be selectively removed from said rigid frame by disconnecting the respective bearing caps from the respective cross member.

2. Apparatus as defined in claim 1 comprising three of said head augers.

3. Apparatus as defined in claim 1 wherein each of said bearing retainer caps is connected to said cross member by bolts extending generally perpendicular to said head augers.

4. Apparatus as defined in claim 1 wherein said front shaft and said shank shaft are welded to said auger tube.

5. Apparatus as defined in claim 1 comprising for each of said journal bearing units a pair of bearing retainer rings removably secured to the respective cross member and bearing retainer cap and located on opposite sides of said bearing unit to retain said bearing unit in its axial position.

6. Apparatus as defined in claim 5 comprising for each bearing retainer ring a spring compressed seal ring adapted to seal the respective bearing unit from intrusion by solid or liquid matter.

7. Apparatus as defined in claim 5 comprising for each bearing unit of said front bearing housing, a bearing retainer collar located on said front shaft forwardly of said bearing unit and adjacent the respective bearing retainer ring, said collar and said bearing retainer ring defining therebetween labyrinth seal means to prohibit intrusion of dust and dirt therebetween.

8. Apparatus as defined in claim 5 comprising for each bearing unit of said bearing housing, a bearing retaining collar located on said shank shaft forwardly of said bearing unit and adjacent the respective bearing retainer ring, said collar and said bearing retainer ring defining therebetween labyrinth seal means to prohibt intrusion of dust and dirt therebetween. 

1. A multiple cutting head assembly for an earth augering machine having power means for advancing said cutting head assembly into the earth and for providing a rotary drive, said assembly comprising: a rigid frame having a front bearing housing assembly and a rear bearing housing assembly rigidly connected to said front bearing housing assembly, each of said bearing housing assemblies comprising a cross member, a plurality of bearing retainer caps adapted to be removably connected to said cross member and a plurality of journal bearing units, one being retained between each cap and the respective cross member, a plurality of head augers rotatably supported by said frame with their axes parallel and approximately in a common plane, each of said head augers comprising an auger tube with spoil conveying external helical flights, a front shaft rigidly connected to the front end of said auger tubes and journaled in said front bearing housing assembly, a shank shaft rigidly connected to the rearward end of said auger tube and journaled in said rear bearing housing assembly, a rotary cutting head removably secured to said front shaft forwardly of said front bearing housing assembly, and means for connecting said shaft to said power means whereby all of said head augers are rotated in their respective journal bearing units as said cutting head assembly is advanced into the earth and whereby each of said head augers may be selectively removed from said rigid frame by disconnecting the respective bearing caps from the respective cross member.
 2. Apparatus as defined in claim 1 comprising three of said head augers.
 3. Apparatus as defined in claim 1 wherein each of said bearing retainer caps is connected to said cross member by bolts extending generally perpendicular to said head augers.
 4. Apparatus as defined in claim 1 wherein said front shaft and said shank shaft are welded to said auger tube.
 5. Apparatus as defined in claim 1 comprising for each of said journal bearing a pair of bearing retainer rings removably secured to the respective cross member and bearing retainer cap and located on opposite sides of said bearing unit to retain said bearing unit in its axial position.
 6. Apparatus as defined in claim 5 comprising for each bearing retainer ring a spring compressed seal ring adapted to seal the respective bearing unit from intrusion by solid or liquid matter.
 7. Apparatus as defined in claim 5 comprising for each bearing unit of said front bearing housing, a bearing retainer collar located on said front shaft forwardly of said bearing unit and adjacent the respective bearing retainer ring, said collar and said bearing retainer ring defining therebetween labyrinth seal means to prohibit intrusion of dust and dirt therebetween.
 8. Apparatus as defined in claim 5 comprising for each bearing unit of said bearing housing, a bearing retaining collar located on said shank shaft forwardly of said bearing unit and adjacent the respective bearing retainer ring, said collar and said bearing retainer ring defining therebetween labyrinth seal means to prohibt intrusion of dust and dirt therebetween. 